Patrick J wrote:

> And now all of a sudden the pic is rocksolid ! As in it doesnt crash when
> I probe it the worst i can Must have something to do with what Tony said
> about BSF BCF type instructions
>
> Below are the changes made: (just added two BSF)
> LOOP
>   BSF  PORTB, 7 ; port B, bit7:=High
>   BSF  PORTB, 7 ; port B, bit7:=High
>   BSF  PORTB, 7 ; port B, bit7:=High
>   BCF  PORTB, 7 ; port B, bit7:=Low
> GOTO  LOOP  ; Waveform:


I would change that to...

LOOP
   BSF  PORTB, 7 ; port B, bit7:=High
   NOP
   NOP
   BCF  PORTB, 7 ; port B, bit7:=Low
   GOTO  LOOP  ; Waveform:

>
> That is the pin (36)  I now find is VERY sensitive to my scope probe.. when
> thouched the pic crashes (same when touching the pin 1, MCLR)
> No other pins seems sensitive. All pins on portb are connected to LEDs.
> May be a problem in this noisy enviroment.

As I mentioned, it is probably in LVP mode.

All PORTA, PORTC, PORTD and PORTE are floating inputs according to your
code. If they are unconnected then just waving your hand over the PIC
can be enough to upset it.

--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
mailto:sales@bubblesoftonline.com

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